对接端口间相对运动耦合动力学建模

Relative motion coupled dynamic modeling between two docking ports

为提高对非合作目标在轨服务任务的成功率,本文建立了两航天器交会过程的非质心点间耦合相对运动动力学模型。从传统点质量相对运动模型入手,考虑两航天器相对姿态运动和服务航天器绝对姿态运动产生的耦合作用,建立对接端口间的耦合动力学模型。分析耦合作用的种类:航天器所受外力矩产生的动力学耦合;相对姿态四元数、相对姿态角速度和服务航天器绝对姿态角速度产生的运动学耦合。最后设计了滑模控制器,实现对接端口间无碰撞安全对接。数学仿真证明,该耦合作用在交会接近过程中具有显著影响,因此不可被忽略。

In order to improve the success rate of on orbit servicing missions for non-cooperative targets, a coupled relative motion dynamic model is established for two arbitrary points except center points of mass, during rendezvous and docking between a service spacecraft and a tumbling non cooperative target spacecraft. Starting from the traditional point-mass relative motion model, a coupled dynamic model is founded for the two doc king ports considering the coupling effect produced by relative attitude motion of the two spacecraft and absolute attitude motion of the service spacecraft. The type of coupling effect is analyzed： dynamic coupling effect in duced by external moment on spacecraft, kinematical coupling effect induced by relative attitude quaternion, relative attitude angular velocity and absolute attitude angular velocity of the service spacecraft. Finally, a sliding mode controller is designed to achieve safe docking between two docking ports without collision. Numerical simulation results demonstrate that the coupling effect on relative translation is so significant during close proximity and rendezvous that it can＇t be ignored.